#!/usr/bin/env python
# -*- coding: utf-8 -*-
# @Date    : 2020-08-29 23:17:15
# @Author  : Zuo Zhongfei (zuozhongfei@126.com)
# @Link    : www
# @Version : $Id$

import os
import sys
import pygame
from bullet import Bullet


def check_keydown_events(event, ship, ai_settings, screen, bullets):
    # 响应按下按键
    if event.key == pygame.K_RIGHT:
        ship.moving_right = True
    elif event.key == pygame.K_LEFT:
        ship.moving_left = True
    elif event.key == pygame.K_UP:
        ship.moving_up = True
    elif event.key == pygame.K_DOWN:
        ship.moving_down = True
    elif event.key == pygame.K_SPACE:
        fire_bullet(ai_settings, screen, ship, bullets)


def check_keyup_events(event, ship):
    # 响应松开按键
    if event.key == pygame.K_RIGHT:
        ship.moving_right = False
    elif event.key == pygame.K_LEFT:
        ship.moving_left = False
    elif event.key == pygame.K_UP:
        ship.moving_up = False
    elif event.key == pygame.K_DOWN:
        ship.moving_down = False


def check_events(ai_settings, screen, ship, bullets):
    # 响应键盘和鼠标事件
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            sys.exit()

        elif event.type == pygame.KEYDOWN:
            check_keydown_events(event, ship, ai_settings, screen, bullets)

        elif event.type == pygame.KEYUP:
            check_keyup_events(event, ship)


def update_screen(ai_settings, screen, ship, bullets):
    # 每次循环时重绘屏幕
    screen.fill(ai_settings.bg_color)

    # 在飞船和外星人后面重绘所有子弹
    for bullet in bullets.sprites():
        bullet.draw_bullet()

    # 在指定的位置绘制飞船
    ship.blitme()

    # 让最近绘制的屏幕可见
    pygame.display.flip()


def update_bullets(bullets):
    """更新子弹的位置，并删除已经消失的子弹"""
    # 更新子弹的位置
    bullets.update()

    # 删除消失的子弹
    # 删除消失的子弹
    for bullet in bullets.copy():
        if bullet.rect.bottom <= 0:
            bullets.remove(bullet)


def fire_bullet(ai_settings, screen, ship, bullets):
    """如果还没有达到限制就发射一颗子弹"""
    # 创建一颗子弹，并将其加入到编组bullets中
    if len(bullets) < ai_settings.bullet_allowed:
        new_bullet = Bullet(ai_settings, screen, ship)
        bullets.add(new_bullet)
